As a backlight device for irradiating a display panel for displaying an image with light, there is a direct type backlight device in which a light source such as an LED (light emitting diode) or a cold-cathode tube is disposed at a position facing one flat plane of the display panel (for example, see Japanese Patent No. 5066264). In addition, as another backlight device, there is an edge light type backlight device having a light source which is disposed at a position facing an end surface of a light guide plate and irradiates the display panel with light from one flat surface of the light guide plate, the light being made incident on one end surface of the light guide plate from the light source.
Currently, as a display apparatus including the display panel and the backlight device for irradiating the display panel with light, a thin type display apparatus is required. As a conventional edge light type backlight device included in the thin type display apparatus, there is a backlight device including: a backlight chassis for supporting a rectangular light guide plate and for covering the other flat surface of the light guide plate and end surfaces of the light guide plate except for one end surface on which light is made incident from a light source; and a heat dissipater for covering the one end surface of the light guide plate and for dissipating heat of the light source. In the conventional backlight device, a box body, in which one surface facing the one flat surface of the light guide plate is open, is formed by the backlight chassis and the heat dissipater, and the box body houses the light guide plate.
In the conventional display apparatus including the conventional backlight device as described above, in a state in which the rectangular display panel is disposed so that the one surface of the rectangular display panel faces the one flat surface of the light guide plate, a peripheral edge portion of the other surface of the display panel and side walls of the box body formed by the backlight chassis and the heat dissipater are covered with a bezel.